Latest filingSep 10, 2026Most recent Form 4
ACMR
ACM Research, Inc.
NasdaqIndustrialsSpecial Industry Machinery, NEC
Insider activity for last month from 08/11 to 09/11. Counts use processed Form 4 rows. Purchase and sale metrics use codes P and S; totals remain unknown when any matching value is missing. Rows without a usable transaction date cannot be assigned to a rolling period and are excluded.
Total buying$00 buys
Total selling$1.53B15 sells
Net open-market-$1.53B5 insiders
Open-market mix
Buy vs sell distribution by transaction countInsider activity report
Monthly open-market purchase and sale counts Buys Sells
Transaction codes
By Form 4 transaction code in selected period31transactions
- S · Open-market sells · dominant15 · 48%
- M · Option exercise10 · 32%
- A · Grants / awards6 · 19%
Activity by reported role
A joint filing can contribute to multiple roles31transactions
- SR · dominant20 · 65%
- Director11 · 35%
Distinct insiders active
Reporting-owner CIKs by month · peak Aug 2026 (4)Aug 2026Sep 2026
Reported Holdings After
Separated by insider, security, and ownership typeWang David HClass A Common Stock · Direct
808,615Sep 09, 2026
McKechnie MarkClass A Common Stock · Direct
900Aug 20, 2026
Dun HaipingClass A Common Stock · Direct
5,000Aug 18, 2026
Dun HaipingStock Option · Direct
45,000Aug 18, 2026
McKechnie MarkStock Option · Direct
215,000Aug 20, 2026
Wang David HStock Option · Direct
130,000Sep 09, 2026
Dun HaipingRestricted Stock Units · Direct
728Aug 12, 2026
Liu TracyStock Option · Direct
6,400Aug 12, 2026
These are reported post-transaction holdings, not company-wide ownership percentages. Securities, indirect vehicles, and amendments are kept separate.
Filing activity heatmap
Each cell is one day · intensity = transactions · buys green, sells redAug 11 → Sep 11
LessMore
Top insiders
By absolute net value across the selected period- WH-$10.5M
- MM-$3.3M
- DH-$377.7k
Recent filing activity
Most recent 12 transactions · color = transaction codeFiling detail checks
Secondary metrics for the selected periodFiling-only signals
Deterministic matches in the selected period
ACMR transaction history
Filters apply within this company and selected period by default| Ticker | Insider | Role | Type | Shares | Value | Code | Signals | 90d return | Filed | Trans date |
|---|---|---|---|---|---|---|---|---|---|---|
| ACMR | Wang David H | SR | exercise10b5-1 | 70.0k | $0 | M | — | 0.0% | 09/10 | 09/09 |
| ACMR | Wang David H | SR | exercise10b5-1 | 70.0k | $0 | M | — | 0.0% | 09/10 | 09/08 |
| ACMR | Wang David H | SR | sale10b5-1 | 1.10k | -$8.53M | S | — | 0.0% | 09/10 | 09/09 |
| ACMR | Wang David H | SR | sale10b5-1 | 4.80k | -$36.8M | S | — | 0.0% | 09/10 | 09/09 |
| ACMR | Wang David H | SR | sale10b5-1 | 11.6k | -$88.1M | S | — | 0.0% | 09/10 | 09/09 |
| ACMR | Wang David H | SR | sale10b5-1 | 18.9k | -$141M | S | — | 0.0% | 09/10 | 09/09 |
| ACMR | Wang David H | SR | sale10b5-1 | 33.4k | -$247M | S | — | 0.0% | 09/10 | 09/09 |
| ACMR | Wang David H | SR | exercise10b5-1 | 70.0k | $7.00M | M | — | 0.0% | 09/10 | 09/09 |
| ACMR | Wang David H | SR | sale10b5-1 | 1.50k | -$11.7M | S | — | 0.0% | 09/10 | 09/08 |
| ACMR | Wang David H | SR | sale10b5-1 | 12.3k | -$96.2M | S | — | 0.0% | 09/10 | 09/08 |
| ACMR | Wang David H | SR | sale10b5-1 | 51.3k | -$396M | S | — | 0.0% | 09/10 | 09/08 |
| ACMR | Wang David H | SR | sale10b5-1 | 4.80k | -$36.4M | S | — | 0.0% | 09/10 | 09/08 |
| ACMR | Wang David H | SR | exercise10b5-1 | 70.0k | $7.00M | M | — | 0.0% | 09/10 | 09/08 |
| ACMR | McKechnie Mark | SR | exercise10b5-1 | 25.0k | $0 | M | −0.8% | 08/22 | 08/20 | |
| ACMR | McKechnie Mark | SR | exercise10b5-1 | 30.1k | $0 | M | −0.8% | 08/22 | 08/20 | |
| ACMR | McKechnie Mark | SR | sale10b5-1 | 11.2k | -$87.3M | S | −0.8% | 08/22 | 08/20 | |
| ACMR | McKechnie Mark | SR | sale10b5-1 | 30.3k | -$235M | S | −0.8% | 08/22 | 08/20 | |
| ACMR | McKechnie Mark | SR | sale10b5-1 | 13.6k | -$104M | S | −0.8% | 08/22 | 08/20 | |
| ACMR | McKechnie Mark | SR | exercise10b5-1 | 25.0k | $34.7M | M | −0.8% | 08/22 | 08/20 | |
| ACMR | McKechnie Mark | SR | exercise10b5-1 | 30.1k | $58.8M | M | −0.8% | 08/22 | 08/20 | |
| ACMR | Dun Haiping | DIR | exercise10b5-1 | 5.00k | $0 | M | −10.8% | 08/20 | 08/18 | |
| ACMR | Dun Haiping | DIR | sale10b5-1 | 400 | -$3.28M | S | −10.8% | 08/20 | 08/18 | |
| ACMR | Dun Haiping | DIR | sale10b5-1 | 3.40k | -$27.6M | S | −10.8% | 08/20 | 08/18 | |
| ACMR | Dun Haiping | DIR | sale10b5-1 | 1.20k | -$9.63M | S | −10.8% | 08/20 | 08/18 | |
| ACMR | Dun Haiping | DIR | exercise10b5-1 | 5.00k | $2.80M | M | −10.8% | 08/20 | 08/18 |
ACM Research, Inc. Insider Activity FAQ
SEC Form 4 contextWho recently reported transactions at ACM Research, Inc.?
Wang David H, Pappis Charles C, Liu Tracy, Dun Haiping, McKechnie Mark.
When was the latest reported open-market purchase?
No code-P purchase is available for this period.
When was the latest reported open-market sale?
Wang David H reported a sale on Sep 09, 2026 valued at $8.53M. Read the SEC filing.
What is the recent purchase and sale balance?
Net open-market selling in the selected period was $15,300,651.24. Sales can occur for many non-investment reasons.
Where can I see the original SEC filing?
Every transaction row and latest-activity fact links to its original SEC filing.
What do these Form 4 transaction codes mean?
P and S generally describe open-market or private purchases and sales. A, D, F, M, X, G, J, and V describe awards, issuer dispositions, tax withholding, exercises, gifts, other transactions, and voluntary early reports; review each filing and its footnotes for context.